Electrostatic precipitation room air cleaners are very effective at removing particulates from the air and particularly excel when it comes to removing small particles. The filters are cost-effective, as the user does not have to purchase replacement filters on a regular basis, and they may be reused after washing.
One drawback to conventional electrostatic precipitation room air cleaners is that they typically produce ozone. Ozone can also be present as a naturally occurring component of room air. Regulatory bodies have enacted legislation to regulate the production of ozone so that its deleterious effects may be mitigated.
The electrostatic precipitation filtration systems of conventional electrostatic precipitation room air cleaners typically have consisted of an ion emitter and a collector electrode stage cooperative to provide ions and to precipitate ionized particulates out of the air stream. The conventional emitter electrode stage may include an ion source such as, for example, a wire ion emitters. The conventional collector electrode stage typically comprise a plurality of electrically biased flat or uni-planar collector plates.
The ozone produced by such conventional electrostatic precipitation room air cleaners results from the high ionization potential of the ion emitters and from “arcing” between the collector plates that occurs during the accumulation of ionized particulate precipitation onto their collector plates. The level of ozone produced by conventional electrostatic precipitation room air cleaners has typically been controlled to conform to regulated levels by an ozone remediation element. The conventional ozone remediation element is operable to convert controlled amounts of ozone into oxygen just prior to the air exiting the housings of such conventional electrostatic precipitation room air cleaners.
The two stage electrostatic precipitation systems of conventional electrostatic precipitation air cleaners have typically required multiple ion wires emitters and cooperative ion stripper plates in order to provide a clean air delivery rate (CADR) sufficient to clean a room of ordinary size. Not only does the cost increase according to the number of wires employed, but the quantity of ozone also increases. Since the multiple wire ion emitters are each subject to their own corona discharge, the quantity of ozone increases according to the number of wires employed.
Another problem with the two stage electrostatic precipitation systems of conventional electrostatic precipitation air cleaners is the arcing that may occur between the electrically biased collector plates. Arcing between the collector plates may occur because large particles of dust or other debris have bridged the space between two of the biased collector plates. Conventional electrostatic precipitation air cleaners have responded by placing additional filters prior to the ion emitter to prevent such large debris from entering the electrostatic precipitation system. The addition of this filter increases the cost of the device.
Yet another reason arcing may occur is when one of the flat or uni-planar biased collector plates is distorted, so as to reduce the space between itself and the adjacent biased collector plates. When this space is reduced sufficiently, an electrical arc can occur between the plates. Conventional electrostatic precipitation air cleaners have responded by adding additional structures between the flat or uni-planar biased collector plates, such as, for example, spacers. Not only do such spacers increase the cost of the device, they also inhibit air flow. These spacers also have been found to collect debris, and debris accumulation may be sufficient to bridge the space between the flat or uni-planar biased collector plates and cause electrical arcing to occur.